Document Type : Original Research Paper


1 Ph.D. Student, International Campus, Ferdowsi University of Mashhad, Mashhad, Iran

2 Professor, Department of Geology, Ferdowsi University of Mashhad, Mashhad, Iran

3 Assistant Professor, Department of Geology, Payame Noor University, Tehran, Iran

4 Associate Professor, Department of Geology, Islamic Azad University,Mashhad Branch, Mashhad, Iran


In the present study the Abderaz Formation ostracods were investigated. The thickness  of the formation in this section is 385m, and consists of shale and marl together with three horizons of chalky limestone. Paleontological studies led to identification of 16 genera and 51 species of ostracods and differentiation of four  biozones in this section. According to the ostracods and correlation with calcareous nannofossils in this section, an age of late Santonian to early late Campanian is quoted to the formation at this section.  Presence of warm water index species and absence of cool water forms suggest warm surface waters. Also changes in depth and oxygen were concluded during depositional course of the formation.


Al-Shareefi, I. Y., Khalaf, S. K. and Al-Eisa, M. A., 2010- Paleoecology of some Upper Cretaceous Formations from Selected Wells Northwest and Middle Iraq. Iraqi Journal of Earth Sciences, 10 (2): 67-96.
Benson, R. H. and Sylvester-Bradley, P., 1971- Deep-sea ostracodes and the transformation of ocean to sea in the Tethys. Bulletin du centre de recherches de Pau, 5: 63-91.
Ceolin, D., Fauth, G. and Coimbra, J. C., 2011- Cretaceous-Lower Paleogene ostracods from the Pelotas Basin, Brazil, Palaeobiodiversity and Palaeoenvironments. International journal of palaeontology and stratigraphy, 91: 111-128
Gerson Fautha, G., Seeling, J. and Luther A., 2003- Campanian(Upper Cretaceous) ostracods from southern James Ross Island, Antarctica, 84: 105-119
Gebhardt, H. and Zorn, I., 2008- Cenomanian ostracods of the Tarfaya upwelling region (Morocco) as palaeoenvironmental indicators. Revue de micropaleontology. 51: 273-286.
Grosdider, E., 1973- Associations d' ostracodes du Cretace d' Iran,Rev.Inst .fr.Petrol. 28. 131-168 P.
Khalaf, S. K. and Aziz, N. M., 2009- On Some Species of the Ostracode Genera Cytherella, Bairdia and Bairdoppilata From Avanah Formation, Dohuk Area, Northern Iraq. Tikrit Journal of Pure Science, 14 (3): 1813–1662.
Luger, P., 2003- Paleobiogeography of late Early Cretaceous to Early Paleocene marine Ostracoda in Arabia andNorth to Equatorial Africa.Palaeogeography, Palaeoclimatology, Palaeoecology 196, 319-342.
Monostori, M. and Ephraim, G., 1985- Eocene ostracoda from the Dorog Basin (Northern Transdanubia, Hungary). Akademiai kiado, Budapest, 213p.
Moore, R. C., 1961- Treatise on Invertebrate Paleontology, Part Q, Arthropoda; Crustacea, Osteracoda. Geological. Society of America and Univ. Kansas, 422 p
Neale, J. W., 1964- Some factors influencing the distribution of Recent British Ostracoda. Pubblicazioni della Stazione Zooligica di Napoli, 33: 247-307.
Shahin, A., 2005- Maastrichtian to Middle Eocene ostracodes from Sinai, Egypt: Systematics, biostratigraphy and paleobiogeography. Revue de Paleobiologie, 24(2): 749.
Sissingh, W., 1977- Biostratigraphy of Cretaceous calcareous nannoplankton. Geol Mijnbo, 56: 37-65
Sohn, I. G., 1962- The ostracode genus Cytherelloidea, a possible indicator of paleotemperature. United States Geological Survey professional paper 450-D, 162: D144-147.
Szczechura, J., 1965- Cytheracea (Ostracoda) from the uppermost Cretaceous and Lowermost Tertiary of Poland. Acta Palaeontologica Polonica, 10 (4): 451–564.
Whatley, R. C., and Coles, G., 1987- The late Miocene to Quaternary Ostracoda of Leg 94, Deep Sea Drilling Project. Revista Española de Micropaleontologia, 19 (1): 33-97.
Whatley, R. C., Bajpai, S. and Whittaker, J. E., 2003- Indian intertrappean ostracoda in the collections of the Natural History Museum, London. Cretaceous Research, 24 (1): 73-88